At present, gas water heaters on the market typically include: D type (natural exhaust type) gas water heaters, Q type (forced exhaust type) gas water heaters, P type (natural exhaust and air supply type) gas water heaters, G type (forced exhaust and air supply type) gas water heaters and W type (outside set-up type) gas water heaters and so on. Q type and G type gas water heaters are provided with exhaust fans directly, so as to forcedly exhaust waste gas generated when burning gas, such that the residual gas explosion or the like may be avoided.
In the related art, the Q type gas water heater mostly adopts a wind pressure detecting unit to detect the wind pressure at an air outlet and controls the exhaust fan and an igniter unit according to the detected wind pressure, so as to ensure that the gas water heater may work normally. Although the combustion operation of the gas water heater in the case of the wind flow backward may be avoided by adopting the wind pressure detecting unit, the device cost is high, and the operation of the gas water heater may be interrupted due to the slight wind pressure, such that the user is unable to use the gas water heater normally.